Allen-Bradley 1734-SSI, Руководство пользователя, Страница: 24 / 48

24 Rockwell Automation Publication 1734-UM007E-EN-P - October 2015
Chapter 3 Communicate with Your Module
The following table shows the Instance Services provided by the Parameter
Object (Attribute = 1).
Operating Modes The operating modes of the 1734-SSI module are essentially the parameters you
set through the RSNetWorx EDS file. This table lists parameters you set.
Parameter Service Field Bytes
1 Get Present SSI Word 4
2 Latched SSI Word 4
3 SSI Status Word 2
4 Get/Set Run 1
5 Gray/Binary 1
6 SSI Word Length 1
7 Data Rate 1
8 Gray to Binary Conversion 1
9 SSI Word Delay Time 2
10 Standardization 1
11 Trailing Bits 1
12 Sensor Resolution 2
13 Sensor Cycles 2
14 Latch Input Control 1
15 Comp 1 Control 1
16 Comparator 1 Value 4
17 Comp 2 Control 1
18 Comparator 2 Value 4
19 SSI Word Filter Control
(1)
(1) This parameter is present in firmware version 4.001 and later.
1
Parameter Value
(1)
Notes
Run Enable /Disable Turns SSI data clock on or off
Data Type Binary or Gray SSI sensor’s data type
Data Word Length 2...31 ( 13 ) Length of the received serial data word can
be any size between 2 and 31 data bits. Bit
32 is used for Latch Input detection.
Data Rate 125 /250/500K baud, 1/2M baud Speed of SSI data clock
Gray to Binary Conversion No /Yes Convert data from Gray to binary
SSI Word Delay Time (t
m
) 16
μ
s... to 64ms ( 64
μ
s ) Delay time between successive SSI data
words
SSI Word Filter Control Off, Low, Med, High, Max Corresponds to the number of successive
equal SSI data words that must be received
by the module in order to update the real-
time present SSI data word.
Standardization Off /On Off = Use entire data word length specified
by Data Word Length parameter.
On = Data is right-shifted the number of bits
specified in the Trailing Bits parameter.